Over the years, there have been numerous variations of locking devices for a multiple of applications. Typically, a locking device is used to secure objects together, whether it be two independent items, a door for an enclosure, or the like. A locking mechanism may be either key actuated wherein a key is used to turn a locking core or are of a combination type wherein a set of disks are manipulated based on a code.
A widely used locking device is known as the padlock. The standard padlock includes a housing containing the lock core and latch elements. A U-shaped shackle extends from the housing with one leg of the U-shaped shackle being pivoted with respect to the housing. When the padlock is in an unlocked state, the shackle may be rotated so that a free end of the shackle may be inserted through openings, around an object, or the like. The shackle is then rotated back to the alignment and compressed into the housing so that the free end becomes latched by the latching structures contained therein.
The prior art padlock works adequately for a number of conventional applications when the span of the objects to be secured is relatively short or when the span can be fitted with a hasp. However, where the span is larger, it is sometimes difficult to employ a traditional padlock due, in part, to the curvature of the shackle. For this reason, some padlocks are provided with a shackle having elongated legs. In most instances, however, it is desirable to create a locking structure that is resistant to tampering or compromise. Since one of the weakest points in a lock is the shackle, it is desirable that the shackle have reduced accessibility when it is used for its designated purpose. Padlocks having these U-shaped shackles may be subjected to compromise however since the elongated dimension of the legs allows access such that the lock may be cut or broken off of the objects which it is to secure.
Another type of locking device related to the padlock may be referred to as a “locking pin”. Here, a shackle includes an elongated shaft having a stop portion such as an enlarged head formed at one end and a latching portion opposite the stop portion. A locking head is then releasable and lockably securable to the latch end of the shackle. The locking head carries a lock core and latch elements to engage the latch structure. While such a device is quite useful in covering longer spans, it has the disadvantage in that the two pieces of the lock are separable so that one may readily become misplaced.
One industry wherein a wide variety of locking devices are employed is the towing industry, especially the recreational vehicle towing industry. Here, a trailer vehicle, such as utility trailer, recreational trailer or the like is towed by a tractor vehicle, such as a car or truck. It is necessary to link the tractor vehicle to the trailer vehicle by some form of a tow hitch. Typically, a hitch ball is secured to the tractor vehicle either directly to the frame or by way, of a hitch receiver and hitch bar. The trailer vehicle has a tongue that carries a coupler in the form of a hitch ball receiver and a lever like latch is used to secure the hitch ball receiver onto the hitch ball in a releasable manner. In such an arrangement, numerous releasable connections are present and may be subject to compromise and result in the theft of the trailer vehicle. For example, where a hitch receiver and hitch bar are used, removal of the hitch pin that secures them together will allow the trailer vehicle to be removed even though the hitch ball remains in the hitch ball receiver since the tow bar is removed from the hitch receiver. Therefore, the use of locking hitch pins is known. Further, since the lever latch securing the hitch ball receiver to the hitch ball may be used to release the hitch ball, it is known to lock the lever lock or “coupler” to prevent unwanted detachment of the trailer vehicle from the tractor vehicle.
In order to lock the coupler, a conventional padlock may, and commonly is used. However, a substantial portion of the shackle of such a traditional padlock is exposed so that it is not difficult to cut the padlock off of the trailer coupler lever thereby allowing manipulation of the lever either to remove the trailer from the tractor vehicle or to gain access to the hitch ball receiver to attach another tractor vehicle. While pin type locks may be used to lock the trailer hitch coupler lever, these devices are also subject to attack, for example, by a hacksaw, that is used to sever the shaft of the shackle thereby allowing it to be released from the vehicle.
As a result of these disadvantages, there has been a long felt need for better locking mechanisms, especially for use with trailer hitch couplers. There is a need for a locking device that is subject to attack and compromise. There is a further need for locking devices that are more conveniently employed in trailer hitch coupling applications. The present invention is directed to meeting these needs.